1. Technical Field
The present invention relates generally to radio frequency (RF) identification systems, and more particularly, to a test fixture for evaluating an RF identification system and related methods.
2. Related Art
Highly automated manufacturing facilities, such as those in the semiconductor industry, track product movement of a product throughout a facility using a radio frequency (RF) identification system. Typically, these systems include an RF tag mounted to the product and RF antennas placed at load ports within a manufacturing facility to sense and read RF tags on the product containers. The ability to read RF tags repeatedly and accurately within the manufacturing facility is a critical component of the automation system. An antenna's sensing field is three dimensional. The alignment of an antenna to the RF tag enables each load port that receives the product container having an RF tag to read the information contained on the RF tag. Tag reading, however, is affected by external fields, metal objects, and positioning and alignment of the antenna.
One challenge for these automation systems is making “in-the-field” adjustments to ensure proper reading of RF tags. “In-the-field” adjustments are difficult because, inter alia, surrounding metal, obstructions and other RF field parameters affect the shape of the antenna sensing fields. One approach to provide “in-the-field” adjustments is to conduct testing using a hand held field strength meter, which senses the strength and location of an antenna's sensing field. This approach, however, suffers from a number of drawbacks. First, field strength meters use a different antenna than the in-situ antenna. As a result, they do not replicate the actual tag and actual antenna interaction. Second, field strength meters are hand held and, therefore, prevent accurate repeatability of positioning during testing. As a result, field strength meters provide only a general indication of antenna performance because they do not accurately replicate the read capability of the RF tag in situ. Finally, since field strength meters evaluate an antenna's sensing field only, they provide no functioning that allows verification of tag performance.
In view of the foregoing, there is a need in the art for a solution that addresses the problems of the related art.